How to call fragment method from main activity

问题

I have method in fragment class. I want to call that method from main activity but I don't want to use FragmentById (or) FragmentByTag.

My fragment method:

public void setItemFromDrawer(String sourceTag, String destTag) {
    //dosomething
}

How to call above method from main activity without using FragmentById (or) FragmentByTag?

回答1:

First create an interface

public interface MyInterface
{
    void myAction() ;
}

Your fragment must implement this interface.

public MyFragment extends Fragment implements MyInterface

In your activity, define a field of type MyInterface :

  private MyInterface listener ;

  public void setListener(MyInterface listener)
  {
     this.listener = listener ;
  }

When creating your fragment and adding it :

setListener(myFragment);

Finally, when the condtion happens that you want to call the Fragment method, just call :

listener.myAction() ; // this will call the implementation in your MyFragment class.

回答2:

it means your calling a fragment method

((YourFragmentClass) fragment).Yourmethod();

回答3:

To better explain the answer by user5466222 :

YourFragmentClass fragment = new YourFragmentClass();
((YourFragmentClass) fragment).yourmethod();

回答4:

In Activity use something like this where you load your fragment:

FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(container, fragment);

transaction.addToBackStack(null); // if you want to store transaction        
transaction.commit();
currentFragment = fragment; // currentFragment is global Fragment variable

Use following line where you want to call fragment's method

currentFragment.setItemFromDrawer("sourceTag","destTag");

回答5:

((YourFragment Class) fragment).Your method();

its worked form me

来源：https://stackoverflow.com/questions/35747346/how-to-call-fragment-method-from-main-activity

标签

java

android

android-fragments

android-activity

fragmentmanager